Stereospecific synthesis of spiro-cyclopropanes
Written by sctunisie no commentsThe addition of 2-diazopropane (DAP) 1 with 2-arylidenindan-1-ones 2a-c has led exclusively to spiro-pyrazolines 6a-c. When the two faces of dipolarophile are not equivalent (case of 2d-f) the addition gave two spiro-pyrazolines 7d-f and 8d-f diastereoisomers. Pyrazoline 7d-f resulting from DAP approach on the less bulky face of enone is unstable and evolves spontaneously to the ethylenic derivatives 9d-f. Photolysis of 6a-c and 8d-f has led to spirocyclopropanes 10a-c and 11d-f with stereospesific manner.
R. Gharbi, J. Lachheb, M. T. Martin, Z. Mighri, A. Khemiss
Pages 245-255
